Obesity rates in preschool children are high and disproportionately affect low-income children of color in the USA. Since 80% of preschool children spend [approximately] 40 h/week in out-of-the home childcare, childcare centers are promising sites for obesity prevention interventions. Mixed methods were used to develop, implement, and assess the feasibility of an obesity prevention program for children 2-5 years. The intervention which consisted of brief (1-3 min), interactive, educational modules was developed by content experts and parents (n = 20) and targeted four areas (milk, sugar sweetened beverages, screen time, and physical activity). The modules were delivered by community health workers in the childcare center during pick-up and drop-off times, in small groups and home visits upon request. Focus groups with childcare center staff (n = 28) assessed satisfaction and interest in incorporating the intervention into care. Between February 2013 and March 2014, 354 caregivers ([approximately] 73%) at six centers participated in one or more educational sessions. Of children, 37.4% in 2013 and 35.9% in 2014 were overweight or obese. Children entering preschool in 2014 were more likely to be overweight/obese than children who had been in the center since 2013 (36.2 vs 23.2%, p 0.05). Childcare staff endorsed the intervention and received training to continue the program. Brief, interactive health-related behavior-change interventions engaged large numbers of low-income caregivers at childcare centers and resonated with center staff. Childcare center staff represent an underutilized resource to combat the childhood obesity epidemic. (author abstract)